0521779407-19 CUNY1086/Karliner 0 521 77940 7 June 6, 2007 17:50
Staphylococcal Infections 1371■Most humans become intermittently colonized withS. aureusin (by
order of frequency) the nasopharynx (most), skin, vagina (as in toxic
shock syndrome) and rectum
■The skin is an effective barrier to infection and when integrity is dis-
rupted as in surgery, intravenous lines or trauma,S. aureusmay gain
entry and create its trademark local abscess lesion, with subsequent
dissemination
■S. epidermidisis a common colonizer of skin
■Infection related to intravenous catheters and insertion of other
devices; wounds can also give rise to osteomyelitis
Increasing prevalence of methicillin-resistant S. aureus without
recent hospitalization – community acquired or CA-MRSA. Strains are
distinct from hospital strains. Has been reported as a cause most com-
monly of skin and soft tissue infection and has been associated with risk
groups including MSM (men who have sex with men) athletes, military
personnel.
S. aureus isolates intermediate or resistant to vancomycin have also
been reported in hospitalized patients.Signs & Symptoms
■Skin and soft tissue disease:
➣Primarily due to S. aureus
➣Folliculitis:
➣Local infection of hair follicle seen as raised, tender pustules at
the base of a hair follicle
➣Furuncles (boils):
➣Begin as a tender, erythematous nodule that becomes more fluc-
tuant
➣Sometimes creamy discharge; hairy areas of body; usually one
hair follicle involve
➣Carbuncles:
➣Deeper seated infection; sinus tracts can develop; may be asso-
ciated with more systemic symptoms with fevers and chills; mul-
tiple follicles involves
➣Impetigo:
➣Superficial infection; usually localized to exposed skin (face,
extremities)
➣Multiple lesions of different ages; honey-colored crusting
➣Cellulitis:
➣May develop as an extension of the processes outlined above;
indistinguishable from infections caused by Streptococcal spp